Non-working Jawari

Started by Microscope, April 11, 2011, 03:40:47 PM

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Microscope

Anyone have any ideas on this one?  I've built a Jawari from this stripboard layout (http://sites.google.com/site/insideloop/JawariStripboard.jpg).  I get the clean signal when it's off and the LED lights up when it's on but I don't get any sound.  Transformer backward?  Transistor backward?

Since I can't get an image to upload here: http://www.flickr.com/photos/kevincsmith/5610444013/in/photostream

StereoKills

We need a bit more info to help you out!

Read this and you'll see exactly what info to post!
http://www.diystompboxes.com/smfforum/index.php?topic=29816.0
"Sometimes it takes a thousand notes to make one sound"

Paul Marossy

Transformer can't be backwards, the primary and the secondary are the same (10K:10K). Maybe the transistor is in the circuit wrong...

Tony Forestiere

Quote from: StereoKills on April 11, 2011, 03:48:34 PM
We need a bit more info to help you out!

Read this and you'll see exactly what info to post!
http://www.diystompboxes.com/smfforum/index.php?topic=29816.0
+1

Plus , looking at the light bouncing through the trace side of your strip-board/vero, I don't see any lighter areas showing trace cuts.
Could be my old eyes ;)
Post your info following the guide above and good luck.
"Duct tape is like the Force. It has a light side and a dark side, and it holds the universe together." Carl Zwanzig
"Whoso neglects learning in his youth, loses the past and is dead for the future." Euripides
"Friends don't let friends use Windows." Me

Paul Marossy

Quote from: Tony Forestiere on April 11, 2011, 06:37:58 PM
Plus , looking at the light bouncing through the trace side of your strip-board/vero, I don't see any lighter areas showing trace cuts.
Could be my old eyes ;)
Post your info following the guide above and good luck.

Good point. Yeah, if you didn't cut the tracks under the transformer and in the other two places, that might be your problem right there. That's what the box with the dot inside of it indicates - to cut the copper at that location.

Mark Hammer

Like I keep reminding people, despite having only 3 pins, there are at least 847 ways for the pin connections to be wrong. :icon_wink:

Get yourself a datasheet for the JFET you are using, from the company who makes it, and confirm that the pins are exactly the ones you think they are.

Microscope

Here's an update: I did cut the stripboard traces so I don't think that's the issue.  I checked the datasheet and the JFET is oriented properly.  When I use an audio probe (like this one: http://www.diyguitarist.com/PDF_Files/DIY-AudioTester.pdf) to follow the circuit starting at the input, I get a signal at the top (row e) of R1 but not the bottom (row g) and on the S and G (rows d and e) of the JFET but not the D (row c, I get sort of a static sound here) and that's about it.  I've never used a probe like this before.  Does this sound like a bad component(s)?

StereoKills

Quote from: Microscope on April 12, 2011, 01:14:26 PM
Does this sound like a bad component(s)?

Only way to really tell is for you to use a multimeter and post the voltages per: http://www.diystompboxes.com/smfforum/index.php?topic=29816.0
"Sometimes it takes a thousand notes to make one sound"